Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
Chemical depolymerization of chitosan was obtained in the solid state by means of gaseous HCl. This new method allowed us to simultaneously form the hydrochloric salt and saturate the hydration water with acid. The depolymerization was carried out by keeping the product at a given temperature for the desired time. The…
Molecular-dynamics simulations were performed to clarify the structures of SrO and BaO layers on a ${\mathrm{SrTiO}}_{3}(001)$ substrate at the atomic level, and to predict an appropriate buffer layer for ${\mathrm{YBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{7\ensuremath{-}x}/{\mathrm{SrTiO}}_{3}$ heterojunction. The atom…
We introduce a method for examining the boundaries between periodic block copolymer morphologies using self-consistent field theory (SCFT). The technique is illustrated on kink grain boundaries in the AB diblock copolymer lamellar phase. In agreement with experiment, the A and B domains evolve from a simple “chevron”…
The magneto-optical (MO) spectra of 15 ternary ferromagnetic compounds are investigated on the basis of local-density band-structure calculations. The key material of interest in this study is PtMnSb, for which the MO Kerr spectra are unusually large and quite different from that of, e.g., the isoelectronic compounds…
Kerr-lens mode-locked Kr-laser-pumped Cr:LiSGaF and Cr:LiSAF lasers containing only two newly developed low-loss chirped mirrors instead of conventional dielectric resonator mirrors and generating pulses of widths as small as 14-fs with as much as 100 mW of average output power are reported. We report what is to our k…
Infrared spectra obtained from Czochralski (CZ) silicon heated in the range $1100<~T<~1300\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$ in ${\mathrm{H}}_{2},$ ${\mathrm{D}}_{2},$ or mixtures of the two gases, show vibrational absorption at $1075{\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ due to perturbed bond-cen…
The electronic properties of bis(2,6-bis(pyrazol-3-yl)pyridine)iron(II) triflate depend markedly on the extent of hydration. The trihydrate is low spin while the monohydrate is high spin at room temperature but undergoes a discontinuous transition to low spin at low temperatures. In the anhydrous complex magnetic and…
The two-dimensional silicon backbone structure of planar polysilane and W\"ohler siloxene is responsible for their exciting luminescing properties. We have prepared single crystals of siloxene by a topotactic reaction from crystalline CaSi${}_{2}$. The chemical composition was determined as [Si${}_{6}$H${}_{3}$(OH)${}…
N-vinyl-n-butyramide (NVBA), N-vinylisovaleramide (NVIVA), and N-vinyl-n-valeramide (NVVA), which are N-vinylalkylamides with different alkyl groups were synthesized and their solution behavior in a polymeric form was examined. Copolymers of N-vinylisobutyramide (NVIBA) with N-vinylacetamide (NVA), NVIBA with NVVA, an…
Oligonucleotide dendrimers were synthesized using a novel phosphoramidite synthon, tris-2,2,2-[3-(4,4'-dimethoxytrityloxy) propyloxymethyl]ethyl- N , N -diisopropylaminocyanethoxy phosphoramidite. Label, incorporated using [gamma-32P]ATP and polynucleotide kinase, was increased in proportion to the number of 5'-ends.…
The nonexponential response of propylene carbonate and glycerol near their glass transitions could be selectively altered using nonresonant spectral hole burning (NSHB) experiments. This observation provides evidence of the existence of a distribution of relaxation times in these supercooled liquids. NSHB is based on…
The surface structure of ${\mathrm{TiO}}_{2}(110)$ has been reexamined using scanning tunneling microscopy (STM), especially in terms of its temperature dependency. A dramatic topographic change was observed around 725 K, which is most likely due to the oxygen desorption into the gas phase and the simultaneous diffusi…
Using a low-temperature molecular-beam epitaxy growth procedure, ${\mathrm{Ga}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}\mathrm{As}$ --- a III-V diluted magnetic semiconductor --- is obtained with Mn concentrations up to $x\ensuremath{\sim}9%.$ At a critical temperature ${T}_{c}$ (${T}_{c}\ensuremath{\approx}50\mathrm{K}$…
A multiple scattering formulation for the electromigration wind force on atoms in dilute alloys is developed. The theory describes electromigration via a vacancy mechanism. The method is used to calculate the wind valence for electromigration in various host metals having a close-packed lattice structure, namely alumi…
Structural optimization is performed for LaMnO${}_{3}$ with the first-principles pseudopotential method based on the local density approximation (LDA), the generalized gradient approximation, and the LDA+U approximation. The Jahn-Teller distortion is reproduced even by LDA but the magnitude of the distortion for all t…
The phase diagram of doped manganate compounds La_{1-x}A_xMnO_3 (with divalent A) is studied. We analyze an extension of the double exchange model using the Schwinger boson formalism. Earlier work by de Gennes on the existence of a canted phase is reproduced, although this phase is shown to be unstable towards phase s…
The controllability of conductivity and the ease of manufacturing/coating of conducting polymers enable tailor- made dielectric loss components for radar absorbing materials (RAM). Different polypyrrole (PPy) based RAM, e.g. paint/rubber containing PPy powder and PPy coated structural phenolic foams with a gradient of…
The flow behavior and the effect of the spinning conditions on the fiber properties and structure of the copolyesters, i.e., samples of copoly(p-hydroxybenzoate-bisphenol A terephthalate), were investigated. The experimental results indicated that the apparent viscosity was affected significantly by shear rate, melt t…
Highly fluorescent Eu-polymer complexes were synthesized through copolymerization of EuPhen(Nap)2AA with methyl methacrylate or styrene and their luminescent properties were investigated. The Eu-polymer luminophores showed intense red emission under UV excitation, and the emission intensities were much stronger than t…
Die Art des Köders bestimmt die Beute : In einem Teich mit Triethanolamin‐Liganden und Eisen(III)‐Ionen gelingt es, sechs‐ und achtgliedrige Eisencoronate 1 bzw. 2 zu fangen, je nachdem, ob man Natrium‐ oder Caesiumionen als Köder verwendet. Dies ist besonders im Zusammenhang mit der Möglichkeit kombinatorischer Ansät…